1. Field of the Invention
The present invention relates to the installation and support of electronic circuits, such as field-installable memory circuits supported in individual packages such as dice, vertical surface mount packages, lead frame packages and so forth. More particularly, the invention relates to a technique for mechanically and electrically installing such circuit devices on a support, such as a socket or connector on a printed circuit board or motherboard.
2. Description of the Related Art
A wide variety of packaging techniques have been proposed and are currently in use for supporting and interconnecting electronic circuitry, such as memory devices, add-on peripheral circuits, upgrade circuit components, and so forth. Such devices typically include an electronic circuit or circuits formed in or disposed on a support, such as a semiconductor die. The electronic circuitry on the support is designed to function with external circuitry in the ultimate application, such as in a personal computer or other electronic device. To enhance the flexibility of the overall circuit design, it is particularly convenient to provide the separate electronic circuitry in packages which can be assembled on a supporting socket either during factory installation or in the field, such as by end users, local component vendors or service personnel. In such cases, the separately packaged circuitry may be designed to be retrofitted or installed on existing circuit boards as needed such as to further enhance or upgrade the user's system.
Individually packaged circuitry of the type mentioned above may be installed in several manners. For example, the installation of semiconductor dice may be automated in large scale manufacturing processes, particularly when the same or similar circuits are to be added to a large number of circuit boards. However, for after market or add-on circuits, such high-speed installation techniques are inappropriate. Rather, in such applications the circuit package is typically shipped and handled individually or in small groups. Vendors or end users often purchase the circuit packages and individually install the packages in the final application, such as by pressing conductive leads or pads provided on an edge of the package into corresponding sockets in a support or interface connector by hand or by means of conventional tools, such as tweezers.
Such techniques for installing circuit devices suffer from several important drawbacks. First and perhaps most importantly, the circuit device package itself may be quite fragile and easily damaged during handling and installation. Similarly, the circuit board and socket on which the package is installed may often be easily damaged when excessive or improperly-directed force is applied to it during installation. Moreover, increasingly complex add-on circuitry requires a large number of conductive pads or pins extending from the circuit package. These delicate features of the components stand a much greater risk of damage to either the circuit package or to the support in which the package is installed due, again, to excessive force and misalignment. In addition, where the circuits are manually handled and installed, serious damage to the circuits can result from static charges inadvertently conveyed to the circuits by the user or service personnel, or from oils present on the installer's hands.
Various approaches have been proposed and are currently in use for addressing the shortcomings of conventional circuit package installation techniques. For example, the packages supporting the add-on circuitry may be constructed in an increasingly robust manner in an attempt to provide a sturdy framework capable of withstanding handling during transport and installation. However, such packaging adds to the size and cost of the circuitry, and may not effectively reduce the risk of damage to the circuit on which the add-on package is installed. Moreover, to the extent that such techniques still require manual handling and installation, risks associated with static charges and oil from handling may be equally unavoidable.
There is a need, therefore, for an improved technique for handling and installing circuit devices that addresses such drawbacks. In particular, there is a need for an improved system for holding or supporting circuit devices, particularly fragile devices formed on unprotected semiconductor dice, or on dice with limited mechanical protection, during transport, handling and installation. Ideally the technique would reduce or eliminate the need to physically handle the circuit package itself, and would provide for appropriate alignment and securement of the circuit package in a socket or connector.